The invention relates to a process for producing a closure for a medicine bottle having a cap portion with at least one cap opening sealed off by an elastic, puncturable sealing layer and covered by a cover element, wherein the at least one cover element and the cap portion are produced and joined together, and then the elastic sealing layer is injected into the cap portion. The invention further relates to a closure for a medicine bottle, which has a cap portion connectable to the bottle, the cap portion having at least one opening which is sealed off by an elastic, puncturable sealing layer, the opening being closed off on the outside by a cover element which is tightly and releasably connected to the rim of the opening.
German Patent DE 38 35 720 C2 discloses a closure of this kind, which has a pot-shaped cap portion, having on its wall overlapping the opening of the medicine bottle an opening which, in the position of use, is sealed off by a puncturable sealing layer. On the outside of the cap portion a removable film is provided as the cover element, which covers the puncturable area of the sealing layer provided on the opening. On its edge region surrounding the opening the cover film is firmly but releasably attached to the rim of the opening of the cap portion. The puncturable area of the sealing layer is thereby protected from dirt and from the penetration of pathogens.
As a rule, the contents of a medicine bottle of this kind are removed by means of a hollow needle or cannula, which is used to pierce the sealing layer. First of all, the cover film must be pulled upwards or torn off to expose the puncturable portion of the sealing layer.
When producing the closure cap, the cover film is first placed in a molding tool for the cap portion. Then, to mold the cap portion, hot plastic material is injected into the molding tool. The cover element then bonds firmly but releasably to the cap portion. However, it is difficult to adjust the removal or retaining forces for the cover film, such that the film can be easily pulled away from the cap portion, but is still attached to the cap portion firmly enough, so that it cannot become detached during transportation or during the handling of the medicine container. If the removal forces are too great, the gripping tab provided on the cover element can tear off when the cover film is torn off, with the result that the contents of the bottle cannot be removed. However, if the removal forces are too small, there is no longer any guarantee of biological safety, and the puncturable part of the sealing layer may become soiled or come into contact with bacteria, pathogens or the like, when the cover film comes away from the cap portion.